1. Field of the Invention
The present invention relates to a speaker device.
2. Description of the Related Art
Conventionally, various kinds of speaker devices have been disclosed (for example, see JP-B-56-15196 (page 1, FIG. 1) and JP-UM-A-57-106387 (pages 2 and 3, FIG. 1).
FIG. 1 shows an example of a speaker device which is recently often used as a home device or an in-vehicle device. The speaker device 100 is driven by the moving coil system. An annular magnet 104 is placed on a pole yoke 106, and an annular plate 105 is placed on the annular magnet 104. The pole yoke 106, the annular magnet 104, and the annular plate 105 form a magnetic circuit 107.
A voice coil 102 which is wound around an end portion of a voice coil bobbin 103 is placed in a magnetic gap 107a of the magnetic circuit 107. The voice coil bobbin 103 is fixed to a center hole of a cone paper 101 which is a substantially conical diaphragm. A cap 113 is attached to the center hole. An edge 108 is disposed in an outer peripheral portion of the cone paper 101, and attached to an outer peripheral edge of a frame 112 via a paper gasket 114.
A center portion of the cone paper 101 is supported by the frame 112 via a damper 109, so that the cone paper 101, the voice coil 102, and the voice coil bobbin 103 are vibrating available in an integrated state in the direction of the center axis X of the speaker device 100.
Positive and negative input terminals 110 are attached to the frame 112. The ends of the voice coil 102 are electrically connected to the positive and negative input terminals 110 via lead wires (tinsel wires) 111, respectively.
A driving signal (driving current) is supplied from an external power source to the input terminals 110. In the magnetic gap 107a of the magnetic circuit 107, the voice coil 102 then receives an electromagnetic driving force corresponding to the driving signal. As a result, the voice coil 102 is vibrated in the direction of the center axis X of the speaker device 100, integrally with the voice coil bobbin 103 and the cone paper 101, so that an acoustic energy corresponding to the driving signal is radiated from the cone paper 101.
Alternatively, an exciting coil which functions as an electromagnet may be used in place of the magnet 104 to form the magnetic circuit.
In the above-described conventional art, the outer peripheral edge of the damper 109 is bonded to the frame 112. Therefore, resonance of the damper 109 and the frame 112 are transmitted through the damper 109 to be returned to the voice coil 102, thereby causing a problem in that a sound which is delayed and distorted is transmitted to the cone paper 101 to impair the sound quality.
The present invention has been made to solve the above problems, and therefore an object of the invention is to transmit resonance of the damper and the frame through the damper to be returned to the voice coil, thereby impairing the sound quality.
To achieve the above object, according to the invention, there is provided a speaker device comprising: a magnetic circuit including a magnet and a yoke; a voice coil which is placed in a magnetic gap of the magnetic circuit; a diaphragm which is vibrating available in a state where the diaphragm is coupled with the voice coil; and a damper which is placed between a portion of the diaphragm on a side of the voice coil and a housing, wherein the speaker device has a damper holder which is disposed on the housing, and to which the damper is connected, and the housing and the damper holder are in contact with each other via projections which are disposed on one of the housing and the damper holder.